There is an amazing cameo in Deadpool 2 that you probably missed. Given the success of the first movie, it's actually not that hard to imagine that the producers were able to convince a few big names to appear on screen in a small capacity, if only for the fun of it. While a couple of those A-list cameos were easy to spot, this one was pretty easy to miss, but that only adds to the charm of it.
Warning: spoilers ahead for Deadpool 2. If you haven't seen the movie and want to go in blind, best to turn away now. Cable (Josh Brolin) uses time travel and goes back to roughly our present time in order to stop Russell (Julian Dennison) from becoming a tremendous bringer of death in the future. Before Cable first arrives in our time, we see a couple of what can only be described as stereotypical rednecks having themselves a not-so redneck conversation about the inefficiency of toilet paper. The two are drinking beer by their pickup truck in the middle of nowhere when, out of nowhere, Cable shows up and steals their truck.
These two rednecks were actually played by Alan Tudyk of Firefly and Rogue One: A Star Wars Story fame and none other than Matt Damon. Somehow, they were convinced to do this and the movie is all the better for it. The conversation they are having before Cable's arrival has to do with a wiping routine that involves toilet paper, baby wipes and even a blow dryer. This was teased by Rhett Reese in an interview prior to the movie's release with Radio Times. He explained that this actually came from his own life.
"I have a toilet paper manifesto of my own, about the inadequacy of toilet paper. I do this bit about it, and I did it for Ryan. We all looked at each other and said, 'This has to go into the movie somehow.' Then we discussed what caliber actor would we need to do such a scene..."
This isn't the first time that Matt Damon has cameoed in a major superhero movie. Just last year, the Good Will Hunting star appeared briefly but memorably in Thor: Ragnarok as a version of Loki in a play an Asgard. He was pretty recognizable there and was easy enough to spot. In the case of Deadpool 2, both he and Alan Tudyk were wearing wigs, prosthetic bellies, redneck clothes, hats and accents to hide their identities. So nobody would blame you for not being able to spot them on a first watch, but it's something to look out for next time.
Those who have seen Deadpool 2 know that this wasn't the only came to be on the lookout for. Matt Damon's buddy Brad Pitt also made a brief but amazing cameo during the X-Force sequence and a grouping of current X-Men stars finally showed up for a moment in a rather crowd-pleasing fashion. Ryan Reynolds and Fox seem to have outdone themselves in this respect.